_RL ArDvdrFac
ArDvdrFac = vfFacMom*1.
ArDvdrFac = 0.
& +( fVrDw(i,j) - fVrUp(i,j) )*rkSign*ArDvdrFac
fVerV(i,j,kDown) = ArDvdrFac*vrF(i,j)